Automatic laparoscopic ligation clip applicator

Abstract: A laparoscopic ligation clip applicator for automatically applying a plurality of ligation clips includes a handle assembly (10) having an actuator (14), an elongated shaft (12) connected to the handle assembly, and an actuating mechanism (15) disposed within the shaft. The actuating mechanism includes a clamp (26) for engaging a first piece (5) of the ligation clip and a slidable driver (28) for driving a second piece (7) of the ligation clip relative to the first piece. The actuating mechanism also includes a hold (30) for preventing rearward movement of the ligation clips, and an advancer (32) for sequentially feeding the ligation clips. A slidable cam (36), operably connected to the handle assembly, actuates the clamp, the driver and the advancer.

Description: The present invention relates generally to a medical instrument for use with one or more surgical ligation clips. More particularly, the invention is directed to a laparoscopic ligation clip applicator for assembling and clamping a two-piece ligation clip and for automatically feeding each of a plurality of ligation clips to be sequentially assembled and clamped. There are many types of known mechanical applicators for automatically feeding and sequentially closing each of a plurality of conventional ligation clips around a vessel (e.g., a vein, an artery, a cystic duct, and the like.) to be occluded. A conventional ligation clip is typically made of metal and is U-shaped with two extending legs that are bent inwardly by, for example, a known fulcrum type applicator having a scissors-like handle with movable jaws. The jaws close together to crimp the clip about the vessel. Such known applicators house a plurality of ligation clips and automatically feed the clips by using, for example, a biasing mechanism, to sequentially position the ligation clips to be crimped between the movable jaws. Other known ligation clip appliers include movably mounted crimping jaws, and feeding mechanisms for conventional ligation clips, that are actuated remotely through various trigger mechanisms. WO 91/08708 discloses inter alia an arrangement in accordance with the first part of claim 1, and a variety of configurations for suture tie devices and suture tie device applicators, as well as methods of suturing. The suture tie devices generally include at least one leg member having a curved or angled distal, tissue engaging portion. A tying member unidirectionally or bidirectionally displaceable along the leg member can optionally be provided. Engagement of a leg distal portion with a generally opposed leg distal portion or the tying member forms a suture loop which positions organ or tissue material between the curved or angled legs and the tying member. The tying member can be advanced toward the leg member so as to provide variable extent of suture tension. However, further improvements for applying surgical ligation clips are desirable, and in particular, an automatic ligation clip applicator is needed for use with two-piece ligation clips. Those ligation clips provide many advantages over known metal clips since they provide superior clamping strength and may be made of bioabsorbable non-metallic materials. Accordingly, it is a general object of the present invention to provide an improved automatic ligation clip applicator. It is another object of the present invention to provide an automatic ligation clip applicator for use with two-piece ligation clips. It is still another object of the present invention to provide an automatic ligation clip applicator that can house and automatically feed a plurality of ligation clips in a forward direction. It is yet another object of the present invention to provide an automatic clip applicator that can apply a ligation clip using minimally invasive surgery. These objects are attained by the applicator as claimed in claim 1. In accordance with one aspect of the invention, a ligation clip applicator for applying each of a plurality of sequentially fed two-piece ligation clips comprises a handle assembly having an actuator; an elongated shaft having a proximal end connected to the handle assembly, the shaft housing a plurality of two-piece ligation clips, with a distalmost ligation clip in the shaft disposed in a feed position; and actuating means, disposed within the shaft, for assembling and sequentially feeding the ligation clips. The actuating means preferably includes a clamp for engaging a first piece of the ligation clip disposed in the feed position, a slidable driver for driving a second piece of the ligation clip as the first piece is held stationary, and a slidable cam operably engaged with the clamp and the driver and actuable by actuating the actuator, wherein upon actuation of the cam in a cam-forward stroke the clamp engages the first piece of the ligation clip and holds it stationary and the driver drives the second piece in a forward direction to compress the first piece and close the ligation clip. The the slidable cam slides forwardly toward a distal end of the shaft in a cam-forward stroke to advance the driver and the clamp. The cam urges the clamp downwardly to grip the first piece of the ligation clip and the cam also advances the driver to drive the second piece of the ligation clip forwardly and compress the first piece, thus closing the ligation clip. In the preferred embodiment, the ligation clips are aligned axially in a row within the shaft. A desirable means of sequentially feeding the ligation clips includes a stationary holding device provided with retaining springs and serving as a ratchet-type mechanism to prevent movement of the ligation clips in a rearward direction. The ligation clips are advanced forwardly by an advancer connected to a spring-loaded drive means. The drive means is operably connected to the slidable cam and driven in the rearward direction as the cam slides rearwardly in a cam-return stroke. The cam is operably connected to the actuator of the handle and advanced in the forward direction by actuation of the actuator. The cam is driven rearwardly by a cam spring positioned in the shaft. Another feature of the preferred embodiment is the provision of a ratchet mechanism within the handle. This mechanism prevents release of the actuator until a full cam-forward stroke is completed. The actuating means within the shaft is compact enough to allow the shaft to fit through a cannula positioned in the patient's body. In this way, the applicator can be manipulated by the surgeon-user from outside of the body and minimally, or non-evasive, surgery can be performed. A preferred feature of the subject invention is a flexible latch provided in the handle assembly for engaging the separate elongated shaft. As a safety feature, the latch can only be opened when the handle assembly is not being actuated, that is, in an at-rest position. The elongated shaft may also be disposable. In this way, after firing all of the ligation clips the shaft can be released from the handle and discarded, and can be replaced with a new, sterile shaft pre-loaded with an array of ligation clips. In accordance with yet another aspect of the invention, a ligation clip applicator for applying a two-piece ligation clip may comprise a handle assembly having an actuator, and an elongated shaft having a proximal end connected to the handle assembly and housing a plurality of ligation clips, with a distalmost ligation clip in the shaft disposed in a feed position at a distal end of the shaft. Also provided is ligation clip assembling means, disposed within the shaft, for assembling and closing a designated ligation clip disposed in the feed position; ligation clip feeding means, also disposed within the shaft, for advancing the ligation clips in a forward direction within the shaft and positioning a next-to-distalmost ligation clip in the feed position; and a slidable cam operably connected to the handle assembly for movement in a forward direction in a cam-forward stroke and in a rearward direction in a cam-return stroke. During the cam-forward stroke the slidable cam operably engages the ligation clip assembly means to assemble and close the designated ligation clip, and in the cam-return stroke the cam actuates the ligation clip feeding means to advance the ligation clips. In accordance with a preffered aspect of the invention, an automatic laparoscopic ligation clip applicator for applying two-piece ligation clips comprises a handle having a squeezable trigger; an elongated shaft assembly having a proximal end connected to the handle and housing a plurality of two-piece ligation clips arranged in an array, with a distalmost ligation clip in the shaft disposed in a feed position; and a clamp disposed in the shaft assembly for engaging a first piece of a designated ligation clip disposed in the feed position and holding it stationary. In addition, a driver is slidably disposed in the shaft assembly for driving a second piece of the designated ligation clip in the forward direction to compress the stationary first piece and close the designated ligation clip. A holding device is disposed in the shaft assembly and has engaging portions for preventing the array of ligation clips from moving in a rearward direction in the shaft. An advancer is slidably disposed in the shaft assembly for engaging the array of ligation clips and advancing them in a forward direction, and a slidable cam is disposed in the shaft assembly and actuated by the handle to slide in a forward direction in a cam-forward stroke and in a rearward direction in a cam-return stroke. The cam is operably connected to the driver and the advancer. These and other objects, aspects, features and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments taken in conjunction with the accompanying drawings. Figure 1 is a side elevational view of the automatic laparoscopic ligation clip applicator in accordance with the present invention showing a shaft and a handle assembly; Figure 2 is a top plan view of the automatic laparoscopic ligation clip applicator in accordance with the present invention, with a distal end thereof shown partly in cross-section to illustrate a partial array of ligation clips; Figure 3 is an exploded view of the automatic laparoscopic ligation clip applicator in accordance with the present invention showing the components housed within the shaft; Figure 4 is a vertical cross-sectional view of the automatic laparoscopic ligation clip applicator in accordance with the present invention; Figure 5 is an enlarged vertical cross-sectional view of the distal end of the shaft of the automatic laparoscopic ligation clip applicator in accordance with the present invention; Figures 6 through 12 are vertical cross-sectional views of the shaft of the automatic laparoscopic ligation clip applicator in accordance with the present invention illustrating its different operating stages, with Figure 11A being an isolated enlarged view showing a ligation clip positioned in front of a retaining spring of the applicator. For ease of reference, as used herein the term "distal" will refer to that part of the applicator which is farthest from the surgeon-user, and the term "proximal" refers to that part of the applicator which is closest to the surgeon-user. The automatic laparoscopic ligation clip applicator of the present invention is shown generally in Figures 1 and 2 to comprise a handle assembly 10 and an elongated cylindrical shaft 12 attached to the handle assembly at its proximal end. The handle assembly 10 includes a squeezable trigger 14 and a grip 16. The elongated shaft is preferably of a diameter that allows it to be used in minimally invasive surgery techniques. For example, the shaft may have a diameter of 10 mm so it can fit through a cannula communicating from the exterior to the interior of the patient's body. One of the desirable features of the subject invention is the provision of the shaft 12 and the handle assembly 10 as two separate elements removably connectable together. In this way, a disposable shaft can be used with a reusable handle assembly. The disposable shaft can be easily connected to the handle assembly at any rotational orientation in a manner described below. The disposable shaft can be discarded after each surgical procedure and replaced with a clean, sterile shaft pre-loaded with a plurality of ligation clips as will also be described. A plurality of ligation clips are housed in the shaft as shown in Figure 2. As noted above, the ligation clip applicator of the present invention is specifically designed to apply two-piece ligation clips. The two-piece ligation clip 3 can be seen in Figures 2 and 3 to include a Y-shaped clamp 5 and a U-shaped clip body 7. The ligation clip is closed by drawing the clamp 5 relative to the clip body 7 so that legs 7' of the clip body urge arms 5' of the clamp together to compress and occlude a vessel captured between the arms 5'. As shown in Figure 2, the ligation clips are disposed end-to-end in an array within the shaft, with the distalmost ligation clip at the tip of the shaft being in a feed position. Generally speaking, the ligation clip applicator is manipulated to position a designated ligation clip in the feed or application position about a vessel to be occluded, and the handle assembly is actuated to close the designated ligation clip around the vessel. In one complete stroke accomplished by squeezing and releasing the trigger 14, the designated ligation clip at the feed position is closed, ejected from the shaft and the remaining ligation clips are advanced in a forward direction, that is toward the distal tip of the shaft, to sequentially position the next-to-distalmost ligation clip in the feed position. The components for actuating the ligation clips, known collectively as the actuating mechanism 15, are shown in Figure 3. The components are disposed within the shaft 12, which is comprised of two halves, 18 and 20. The two halves of the shaft are keyed to each other and held together by, for example, a shrink tube cover. Each half of the shaft is provided with axially extending raceways for allowing sliding movement of several of the components within the shaft. More particularly, at the distal end of each half 18 and 20 is a raceway 22 for capturing the ligation clips. The raceway terminates at a chamfered end 24 at the distal tip of the shaft. The actuating mechanism 15 is comprised of a clamp 26 and driver 28 which work together to assemble and close the designated ligation clip at the feed position, and a holding device 30 and an advancer 32 which work together to sequentially feed the ligation clips in the forward direction. A drive means 34 is connected to the proximal end of the advancer 32. The actuating mechanism further includes a cam 36 for slidably actuating the driver 28 and the advancer 32, through the drive means 34, within the shaft as will be discussed in detail below. The clamp 26 and the driver 28, which together comprise ligation clip assembly means, work together to assemble and close the ligation clip in the following manner. The clamp 26 is preferably made of a sturdy yet flexible material, such a thin metal, and is shaped to have an elongated slot 38 and a stepped nose portion 40 with an engaging hole 41 for engaging a top post 9 of the Y-shaped clamp 5. A smaller slot 43 in the clamp is used to properly align the clamp within the shaft 12. The driver 28 is also preferably made of a thin, flexible material and comprises a body having a wide portion 42 comparable in width to the clamp 26, and a narrower abutting portion 44 at its distal end with a down-turned nose 45 for abutting the clip body 7 and driving it forward. The wide portion includes a slot 46, shorter in length than the extended slot 38 in the clamp, for receiving a pin 48 on the underside of the cam 36. The clamp 26 is sandwiched between the cam 36 and the driver 28, with the pin 48 extending through the elongated slot 38 in the clamp and slot 46 in the driver. As shown, for example, in Figure 6, the pin 48 has a width narrower than the length of the slot 46 in the driver and thus a lost motion connection is achieved between the cam 36 and the driver. As the cam 36 slides back and forth within the shaft, the pin 48 engages distal and proximal extremes of the slot 46 in the driver and thus slides the driver in the forward or rearward direction. However, the clamp 26 remains stationary within the shaft, as the extended slot 38 is greater in length than the range of sliding motion of the pin 48. As best seen in Figure 5, the distal ends of the clamp 26 and the driver 28, designated by solid lead lines, are bent or inclined upwardly to lie in their unbiased position horizontally above the array of ligation clips. As will be discussed in more detail below, the cam 36 slides forwardly to urge the clamp 26 downwardly and the driver 28 downwardly to assemble and close the designated ligation clip in the feed position. Returning to Figure 3, the holding device 30 and advancer 32, which together with the drive means 34 comprise ligation clip feeding means, work together to sequentially advance the array of ligation clips in the forward direction. Both the holding device and the advancer can be made of a thin flexible metal. The holding device 30, which is positioned between the driver 28 and the array of ligation clips, acts like a ratchet mechanism to prevent rearward movement of the ligation clips. This is accomplished by providing a plurality of flexible, downwardly bent leaf springs 50 each secured at its proximal end to the main body of the holding device 30. Each leaf spring is positioned to engage one Y-shaped clamp 5, comprising each ligation clip, from behind and prevents its movement in the rearward direction. When the ligation clips are advanced in the forward direction, the leaf springs are flexed upwardly and do not inhibit such movement. As seen in Figure 3, the leaf springs 50 are offset from the axial center of the holding device 30 so as not to interfere with the sliding movement of the cam 36 and the driver 28. The advancer 32 is provided to advance the array of ligation clips by sliding back and forth through its connection to the drive means 34. The drive means includes an drive head 52 having a latch 54 that operably engages within one of two drive cut-outs, or slots, 51 and 53 in the cam. The drive means also includes a shaft 55, extending from the drive head, and a compression spring 56 disposed around the shaft. A plurality of leaf springs 58 are preferably punched out of the thin metal advancer 32. The longer leg 59 of each leaf spring is connected to the advancer at its proximal end and engages one of the ligation clips when the advancer moves forward. The shorter leg 61 of each leaf spring acts as a brake to limit the forward movement of the ligation clips. To advance the array of ligation clips, the advancer 32 is slid in the rearward direction toward the handle assembly, where the leaf springs 58 are urged downwardly as they slide under the ligation clips. As the advancer is then advanced in the forward direction, the longer leg 59 of each leaf spring engages a lower side of one of the clip bodies 7 and drives the ligation clips forwardly. The forward movement of the advancer moves the ligation clips sequentially forward so the next-to-distalmost ligation clip advances into the feeding position. Figure 3 also shows a kick spring 60 that is positioned at the distal end of the shaft below the designated ligation clip at the feed position. The purpose of the kick spring is to eject the assembled ligation clip from the shaft in a manner described in more detail below. Figure 4 is a vertical cross-sectional view of the applicator and shows additional details of the handle assembly 10. The trigger 14 is biased to an opened position by a trigger spring 62 and pivots about a pivot point 64. A link 66 is connected to the trigger at pivot point 68 and pivots about pivot point 70 to axially slide an H-drive 72 within a hollow shaft collar 74 of the shaft 12. The H-drive is provided with an abutment end 76 for abutting the proximal end of the cam 36 and an axially slidable spring block 100. The spring block receives a key head 102 of elongated key 104. The key head includes a tab 103 that slides axially and then laterally in an unshown slot in the interior of the spring block to engage therewith. The key 104 extends axially through a cam spring 92, which rests between stationary wall 96 and the key head 102. A ratchet-type mechanism comprises a latch 80 that moves with the H-drive and a notched grate 82 secured in the handle assembly 10. The notched grate is sloped forwardly and upwardly to bias the latch as it moves with the H-drive in the forward direction. As the trigger 14 is squeezed, the latch 80 rides over the sloped notched grate 82. One or more notches in the grate prevent the biased latch from moving rearwardly, and thus the trigger from being released, until the trigger is fully squeezed. When the trigger is fully squeezed, the latch moves out past the distal tip of the notched grate and is biased to its normal position below the distal tip. As the trigger is released, the latch rides below the notched grate and back to its starting position. As discussed above, the elongated shaft 12 and the handle assembly are preferably separate elements that can easily be connected together. In this embodiment, a one-piece engagement latch 84 in the handle assembly 10 secures and locks the shaft 12 to the handle assembly. The distal end of the engagement latch is formed with a tooth 86 for engaging an annular groove 88 on the hollow shaft collar 74. At the proximal end of the engagement latch a flexible member 89 engages a block 90 on the proximal end of the H-drive 72. As will be appreciated from the figure, a small space exists between the engagement latch 84 and the H-drive 72. This space allows the flexible member 89 to be depressed so as to pivot the engagement latch 84 about its pivot point 91 and raise the tooth 86 out of engagement with the annular groove 88. As a safety feature, when the H-drive slides in the forward direction, the block 90 moves toward the center of the engagement latch, thus preventing the flexible member from being depressed and locking the shaft to the handle assembly when the trigger is being squeezed. By providing an annular groove 88 on the hollow shaft collar 74 and an abutment end 76 on the H-drive 72, the shaft can be inserted into the handle assembly at any rotational orientation and will still be engaged and actuated by the handle assembly. Cylindrical grip 98 surrounding the collar 74 also allows the shaft to be rotated after engagement to the handle assembly. Figure 4 also illustrates the manner in which the cam 36 is actuated. In a cam-forward stroke initiated by squeezing the trigger 14, the H-drive 72 is forced forwardly to abut and slide the cam in the forward direction toward the distal end of the shaft 12. The H-drive abuts the proximal end of the cam, but it is not secured thereto. The spring block 100 is secured to cam 36 by the protrusion of rib 94 through an unshown slot in the cam. As the H-drive 72 is driven in the forward direction by squeezing the trigger, the cam and spring block slide forwardly in the distal direction. This forward motion causes the cam spring 92 to compress and become charged. When the trigger is fully squeezed, the latch 80 comes out of engagement with the notched grate 82, allowing the trigger to be released. The trigger is released in a cam-return stroke to retract the H-drive back to its rest position. Since the biasing force of the H-drive against the spring block is no longer in effect, the cam spring 92 discharges and pushes the cam 36 in the rearward direction toward the handle assembly. Figures 6 through 12 illustrate the operational steps of the actuating mechanism 15 as the cam is actuated through one complete cam-forward stroke and cam-return stroke. Beginning with Figure 6, the actuating mechanism of the ligation clip applicator is shown in the rest position, with the cam 36 fully retracted within the shaft and the addrive spring 56 unbiased. Thus, the distal ends of the clamp 26 and driver 28 are bent slightly upwardly in their relaxed positions to rest above a horizontal plane defined by the array of axially-aligned ligation clips 3. The pin 48 on the underside of the cam 36 extends through both the elongated slot 38 in the clamp and the slot 46 in the driver. The pin is shown in Figure 6 to rest at a rearward end of the slot 46 in the driver. Also in this position, the latch 54 of the drive means 34 is engaged in the first drive cut out 51 of the cam. When the trigger is actuated in the cam-forward stroke, the cam begins to slide forwardly as shown in Figure 7. With this forward motion, a sloped side of the latch 54 is forced downwardly to disengage the drive means 34 from the cam. Therefore, the cam 36 rides over the drive means 34, and thus the advancer 32, remain stationary as the cam moves in the forward direction. At the distal end of the shaft, the sliding cam downwardly urges the distal ends of both the clamp 26 and the driver 28. The nose portion 40 of the clamp in thus lowered to engage the upper post 9 of the Y-shaped clamp 5 of the designated ligation clip by having that post received in the hole 41. The abutting portion 44 of the driver is likewise lowered to a position immediately behind the clip body 7 of the designated ligation clip. In Figure 5, the clamp and driver are shown in both their normal raised positions by solid lead lines from numbers 26 and 28, respectively, and in their downwardly urged positions by dashed lead lines from numbers 26 and 28, respectively. As will be appreciated, the driver does not slide forwardly with the initial forward movement of the cam 36, because the pin 48 on the cam must first travel the length of the slot 46 in the driver and reach the distal end of the slot as shown in Figure 8. As the cam continues to slide forwardly, the driver is forced to slide in the forward direction by the pin 48 and abuts the clip body 7, that is the second piece, and pushes it forwardly as the nose portion 40 of the clamp holds the Y-shaped clamp 5, that is the first portion, of the ligation clip stationary. Figure 9 shows the completion of the cam-forward stroke. The cam 36 and the driver 28 are in their forwardmost position, with the abutting portion 44 of the driver forcing the clip body 7 around the Y-shaped clamp 5 to close the designated ligation clip. Also at the completion of the cam-forward stroke, the latch 54 of the drive means 34 engages the second drive cut-out 53 in the cam. As best shown in Figures 8 and 9, when the drive latch 54 disengages from the first drive cut-out 51, it rides in a shallow groove 47 underneath the sliding cam until it reaches an abutting portion 44 on the cam. By providing a shallow groove in the cam, reduced stress is applied to the latch 54 as it is urged downwardly and ridden over by the cam. A slanted surface on the abutting portion 45 forces the latch 54 further downwardly as the cam continues to slide in the forward direction past the stationary drive means 34. The latch 54 pops up into the second drive cut-out 53 as the cam reaches the end of the cam-forward stroke and engages the drive means with the cam. This point is reached by fully squeezing the trigger and the cam spring 92, although not seen in Figures 6 through 12, is compressed and fully charged. The beginning of the cam-return stroke is shown in Figure 10. When the trigger 14 is released as discussed above, the compressed cam spring 92 discharges and drives the cam in the rearward direction. As the cam moves rearwardly, it slides over the distal ends of the clamp 26 and the driver 28, and retracts to a position where the distal ends flex upwardly to their rest or normal positions. Lost motion between the cam and the driver takes place as the pin 48 on the cam travels from the distal end of the slot 46 to the proximal end. When the distal end of the clamp flexes upwardly, the nose portion 40 disengages from the closed ligation clip, and the kick spring 60 biases the ligation clip upwardly and ejects it from the distal end of the shaft as shown in Figure 11. As will be appreciated, the upward biasing force applied by stationary kick spring cannot eject the ligation clip in the feed position until the ligation clip is assembled and closed. Before that time the clip body 7 is positioned within the raceway 22 and prevented from moving in the vertical direction. Since the drive means 34 is engaged with the cam, rearward movement of the cam pulls the drive means rearwardly to compress and charge the drive spring 56. The advancer 32 is also pulled rearwardly by its connection to the drive means. The longer legs 59 of the retaining springs 58 on the advancer are flexed downwardly by sliding contact with the ligation clips and move in series to a position behind one of the ligation clips. As the isolation view of Figure 11A illustrates, the longer legs then flex upwardly to their normal positions and engage a notch in the clip body 7 of one of the ligation clips. Toward the end of the cam-return stroke, the drive latch 54 engages a bumper 71 on the interior of the shaft and disengages from the second drive slot 53 in the cam. When the drive means becomes disengaged from the slot, the drive spring 56 discharges to advance the drive means and the advancer in the forward direction. The forward movement of the advancer advances each of the ligation clips, and the next-to-most-distal ligation clip is thus advanced forwardly to the feed position at the distal tip of the shaft thereby to become the next designated clip. The drive latch 54 re-engages with the first drive slot 51 in the cam and the cam-return stroke is completed. Thus it will be appreciated that the present invention provides a unique mechanism for closing a two-piece ligation clip in minimally invasive surgical procedures. Moreover, this invention provides such a mechanism for automatically advancing each of plurality of stored ligation clips to a feed or applying position so that all clips can be applied without removing the applicator device from the surgical site. Still further, since the present invention is specifically designed to apply two-piece bioabsorbable ligation clips in a convenient and reliable manner, all of the advantages attendant on use of such clips are also achieved. Although a specific embodiment of the present invention has been described above in detail, it will be understood that this description is merely for purposes of illustration. Various modifications of and equivalent structures corresponding to the disclosed aspects of the preferred embodiment in addition to those described above may be made by those skilled in the art without departing from the present invention which is defined in the following claims, the scope of which is to be accorded the broadest interpretation so as to encompass such modifications and equivalent structures.

Claims: A ligation clip applicator for applying each of a plurality of two-piece ligation clips (3), each said ligation clip including a clamp (5) and a clip body (7) movable relative to said clamp (5) to close it about a vessel; said clip applicator comprising: means (12) for storing a plurality of said ligation clips (3) in an array with a distalmost ligation clip (3) in an application position; means for releasably holding said clamp (5) of said distalmost ligation clip (3) at said application position; means (28) for moving said clip body (7) relative to said clamp (5), held at said application position, thereby to close said clamp (5); means for releasing said releasable holding means to free said now-closed distalmost ligation clip (3) from said application position; and means for advancing another ligation clip (3) from said array to said application position; characterised by retaining springs (50) for preventing movement of the ligation clips (3) in a rearward direction and said advancing means including an advancer (32) slidable relative to the ligation clips (3) for sequentially advancing the ligation clips (3) in the forward direction and positioning a next-to-distal-most ligation clip (3) in the feed position in said storing means (12); and by a spring-loaded drive means (34) connected to said advancer (32) for automatically driving the advancer (32) forwards towards the distal end of the applicator at the end of the cam-return stroke, and a slidable cam (36) for actuating said clip body moving means (28) and said advancer (32), said cam being operably engaged by said drive means (34) and moving it in the rearward direction during a cam-return stroke to charge said spring-loaded drive means (34), wherein said drive means (34) disengages from said cam near the end of the cam-return stroke and discharges forwardly to drive said advancer in the forward direction to engage and advance the ligation clips (3). A ligation clip applicator according to Claim 1, further comprising a cam spring connected to said cam and supported in said storing means, wherein said cam spring is charged during a cam-forward stroke and discharges to initiate the cam-return stroke and retract said cam in a rearward direction. A ligation clip applicator according to Claim 1, wherein said advancer comprises a plurality of springs which are flexed by the ligation clips when said advancer slides in the rearward direction and which engage and advance the ligation clips when said advancer is moved in the forward direction. A ligation clip applicator according to Claim 1, wherein said drive means (34) includes an elongated shaft and a compression spring disposed around said shaft. A ligation clip applicator according to Claim 1, wherein said drive means (34) comprises a drive head, an elongated shaft connected to said drive head, and a compressing spring mounted on said elongated shaft, said compression spring being compressed by movement of said drive head in the rearward direction. A ligation clip applicator according to claim 5, said drive head having a flexible latch engageable with a drive slot in said cam, wherein said flexible latch engages said drive slot in the cam-return stroke and said drive means (34) is advanced in the rearward direction to compress said drive spring, said latch disengages from said drive slot near the end of the cam-return stroke and said drive spring discharges to advance said drive means (34) and advancer in the forward direction whereupon said advancer engages the array of ligation clips and moves them in the forward direction. A ligation clip applicator according to Claim 1, wherein said releasable holding means includes clamping means for holding stationary the clamp of the distalmost ligation clip, and said moving means includes a slidable driver for driving the clip body of the distalmost ligation clip in the forward direction to compress the clamp and close the distalmost ligation clip. A ligation clip applicator according to Claim 7, wherein said clamping means and said slidable driver are both operably engaged by the cam, and said driver is driven by said slidable cam to slide relative to said clamping means in the forward and rearward directions.

Inventors: DICESARE PAUL C, STEIN JEFFREY A, DICESARE, PAUL C., STEIN, JEFFREY A.
Applicants: AMERICAN CYANAMID CO, AMERICAN CYANAMID COMPANY
Application year: 1994
Main classification: A61B17
IPC codes: A61B17